Adjustment method pipelayer control system

ABSTRACT

An adjusting mechanism (92) is provided between a valve spool (62) and a valve actuating lever (26) whereby with the lever (26) locked in a selected position, the mechanism (92) is manipulated to move an element (99) carried by the valve spool (62) into alignment with an indicator (110) that has been predetermined to be the selected setting of the valve. With the element (99) aligned with the indicator (110), the mechanism (92) is locked so that the valve spool (62) is in the selected setting when the lever (26) is in the selected position. A lockdown apparatus (70) is provided for use in locking the lever (26) in the selected position while the adjusting mechanism (92) is being manipulated. An overtravel prevention apparatus is also provided whereby as a member (22) approaches its predetermined limit of movement, a linkage system (128,132,136,144,146) is actuated which engages with parts (103) on the cable (58) from the actuating lever (26 ) to the valve spool (62) which overrides the actuating lever (26) and moves the actuating lever (26) and the valve spool (62) to a neutral position, preventing the member (22) from moving beyond its predetermined limit.

DESCRIPTION

1. Technical Field

This invention relates to hydraulic actuators and, more particularly, toa mechanism for adjusting a selected position of a valve spool withrespect to a corresponding selected position of an actuating lever andalso for preventing overtravel of a work member.

2. Background Art

In the use of hydraulic actuators for controlling the operation of adevice, such as the controls for raising and lowering the hook of apipelayer or for adjusting the speed for raising and lowering the hookof a pipelayer, and the like, it is quite important that the neutralposition of the control lever corresponds exactly with the neutralposition of the valve so that the operating element will not operatewhen the control lever is in the neutral position. Currently, differenttypes of variable connectors are provided between the control cableextending from the control actuator lever to the valve spool, whichvariable connectors are adjusted in a trial and error method until theneutral position of the actuator corresponds with the neutral positionof the valve.

In addition, in certain hydraulically-driven apparatus, the actuatedmember must not travel beyond a certain point, otherwise damage to themember or to the operating equipment is highly likely. Limit controlshave been provided whereby contact by the member will release a clutchin the drive mechanism so as to disconnect the drive from the member.This requires considerable linkage to extend from the wench to thekickout actuator.

DISCLOSURE OF INVENTION

The present invention is directed to overcoming one or more of theproblems as set forth above.

An adjusting mechanism is provided for setting a valve spool and anactuating lever in a common position. The valve spool extends axiallyoutward from the valve body and has a part on the extending end thereofexterior of said valve body. An indicator is located exterior of thevalve body along the path of movement of the valve spool to indicate aselected position of the valve spool when said part on the valve spoolaligns with the indicator. A cable connects the actuating lever with thevalve spool and has a connector in connecting relationship with saidpart on the valve spool. A lock down knob is provided for locking theactuating lever in a selected position, which position coincides withthe selected position indicated by the indicator. The part on the valvespool and said connector on the cable are adjustable relative to eachother to set the part on the valve spool in alignment with the indicatorwhereby the lever and valve spool are set in a common position.

A limit control is provided for preventing an operating member frommoving beyond a predetermined limit. The control has a bumper whichengages a plunger to move a linkage system that actuates a probe that,in turn, moves the valve spool and actuating lever to a neutral positionto discontinue movement of the operating member.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a crawler-type vehicle incorporating theinvention therein;

FIG. 2 is a somewhat schematic view showing a valve-adjusting mechanismand a kickout mechanism;

FIG. 3 is a somewhat enlarged schematic view of the valve-adjustingmechanism and the connection of the kickout mechanism;

FIG. 4 is a plan view of the actuator lever, slotted plate and lock downhandle;

FIG. 5 is a cross-sectional view taken along the lines 5--5 of FIG. 4 inslightly enlarged form;

FIG. 6 is a cross-sectional view taken along the lines 6--6 of FIG. 4 inslightly enlarged form;

FIG. 7 is a broken away view of the adjusting mechanism and theinterconnection between the kickout mechanism and the valve stem; and

FIG. 8 is a cross-sectional view taken along the lines 8--8 of FIG. 7.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to FIG. 1, a crawler-type vehicle used as a pipelayer 10 isillustrated and includes a frame member 12 upon which is supported anengine encasing housing 14 and a cab 16. A pair of track assemblies 18and 20 are disposed on opposite sides of the main frame 12. A boom 22 isoperatively attached to one side of the vehicle 10 and a counterweight24 is attached to the opposite side thereof. Although this invention isdescribed specifically with respect to the pipelayer illustrated in FIG.1, it is to be understood that it can be used with any hydraulic controlwherever it is desirable or necessary to set a selected position, suchas a neutral position, on a control lever and a valve, and on anyequipment where a member, such as the boom of a pipelayer, and the like,should not move beyond a predetermined point.

Referring to FIG. 2, there is schematically illustrated, a hydraulicactuating system which includes an actuator lever 26 pivotally androtatably mounted about a universal mount 28 carried by the frame 12 ofthe vehicle 10. The actuator lever 26 projects up through a slottedplate 29 having a grid 30 attached to the control surface of the consoleof the cab 16 and which plate 29 is appropriately marked for indicatingthe position of the lever 26 in the grid 30 for raising or lowering theboom, for increasing or decreasing the speed, for setting the brake andfor the neutral position of the associated valves. As illustrated, apair of bellcranks 31 and 32 are pivotally mounted on the frame 12 ofthe tractor with links 34,36, illustrated only by dashed lines,interconnecting the arms 39,41 of the universal mount 28 with the legs38,40 of the respective bellcranks 31 and 32. Link 34 is connected to anaxially extending arm 41 carried by the mount 28 such that the link 34is moved along its axis when the lever 26 is moved from side to sidealong the main track 43 of the grid 30. Bellcrank 31 has a second leg 42which is connected to a control cable 44 extending through a cablesheath 46 for actuating a valve spool 48 of a hydraulic valve.

The second bellcrank 32 has an elongate leg 50 extending at an angle toleg 40 with the lower extremity of the leg 50 being connected to acontrol cable 52 which extends through a cable sheath 54 for connectionto a valve spool 56 of a second hydraulic valve. Connected to anintermediate portion of the elongate leg 50 of the bellcrank 32 is acontrol cable 58 which extends through a cable sheath 60 for connectionto a valve spool 62 of still a third hydraulic valve. It is recognizedas conventional to move the actuating lever 26 laterally or transverselyas allowed by the grid 30 of the plate 29 which will either pivot orrotate the universal mount 28 to actuate one or the other bellcrank31,32, cables 44,52,58 and the valves connected thereto. As an example,if the lever 26 is moved to the left, it will pivot the universal mount28 and thereby cause the link 34 to pivot the bellcrank 31 and move thecable 44 to actuate the valve connected to the valve spool 48. Since thearm 39 of the universal mount 28 is not raised or lowered when the lever26 is moved left or right, the link 36 and the bellcrank 32 will remainin a neutral position. However, as shown in FIGS. 2 and 4, pivoting thelever 26 into any of the branches 63,64,66,68 in the grid 30, whichbranches extend transverse to the main track 43, will pivot thebellcrank 32 which, in turn, will actuate the cables 52 and 58 tooperate the valve spools 56,62. It is important that the position of thelever 26 corresponds exactly with the position of the spool in the valveso that the valve will function to properly raise or lower an apparatus,to speed up or slow down movement of the apparatus, or to apply a brakewith various degrees of force, or the like.

Referring to FIGS. 4, 5 and 6, as well as to FIG. 2, the grid 30 on theplate 29 on the console has a neutral position which is shown in FIG. 4in alignment with the branch 66 and lying in the track 43. A lock-downapparatus 70 is provided for locking the actuating lever 26 in theneutral position. The lock-down apparatus 70 has a shaft 71 extendingthrough a bearing sleeve 72 in a collar 74 fixed in the plate 29. Abracket 75 is secured on the undersurface of the plate 29 and has anopening 76 for receiving a reduced diameter portion 77 of the shaft 71so as to support the shaft 71 vertically. On the exposed end of theshaft 71 is affixed a knob 78 which is keyed at 79 to the shaft 71 sothat turning the knob 78 in a plain parallel to the plate 29 will rotatethe shaft 71 about a vertical axis. An elongate planar latch plate 80 ispivotally mounted on the reduced diameter portion 77 of the shaft 71 andis spring-urged by a coil spring 81 extending between the bracket 75 andthe plate 80 for holding the plate 80 resiliently against the shoulder82 on the shaft 71 and against the mounting collar 74 carried by theplate 29. A pin 84 is affixed to the top surface of the plate 80 withthe longitudinal axis of the pin 84 substantially parallel to thelongitudinal axis of the latch plate 80. A cam-shaped guide 85 issecured to the undersurface of the plate 29 and has an angular ramp 86formed in the edge 87, with said ramp 86 terminating in a stop 88. Theramp 86 and stop 88 form a rest socket into which the pin 84 can nest asshown in FIG. 6. Turning the knob 78 in a counterclockwise directionwill turn the shaft 71 and the plate 80 whereupon the pin 84 on theplate 80 will travel down the ramp 86 thereby depressing the spring 81and moving the plate 80 both axially and radially with respect to theshaft. As shown in dotted lines in FIG. 4, the plate 80 has ahook-shaped cutout 90 at the outer end thereof, which cutout 90 islocated in such a way that pivoting the knob 78 will pivot the latchplate 80 into position with respect to the actuating lever 26 so as tonest the actuating lever 26 in the hook of the hook-shaped cutout 90when the actuating lever 26 is in the neutral position. Lock down 70also acts as a safety device to prevent inadvertently bumping the lever26 into an actuating position.

Referring to FIGS. 2, 3 and 7, and assuming that the lock-down apparatus70 has the actuating lever 26 locked in the neutral position, amechanism 92 is provided for adjusting the position of the spool 62 of avalve in the neutral position so that the neutral positions of theactuating lever 26 and the valve spool 62 coincide exactly. In FIG. 7, ahousing 93 is shown attached to a valve body 94, which housing 93 has acover plate 95 which can be removed to gain access to the inside of thehousing. The cable 58, travelling through the sheath 60, moves axiallywith respect to the sheath and into the housing of FIG. 7. Sheath 60 isretained by a retainer 91 in a boss 96 on the housing 93 and is sealedagainst leakage by the ring 97 (FIG. 7) extending between the sheath 60and the inside of the opening 98 in the boss 96. The valve spool 62 hasa washer or collar 99 seated against the end of the spool 62 by a bolt100 threaded into a threaded opening in the end of the spool. Aconnector 102 has a disc-shaped body portion 103 with an internallythreaded boss 104 extending axially from one side thereof and with anaxially projecting, radially disposed key 105 extending from the otherside thereof. The key 105 has a slot 106 facing radially toward the axisof the connector 102. The connector 102 can be moved axially withrespect to the end of the cable 58 by rotating the connector 102relative to the cable 58 whereby the threaded boss 104 will advance orretract the connector 102 relative to the cable 58. The washer 99 nestsin the slot 106 in the key 105 on the connector 102 so that the washer99 and spool 62 are moved axially as the connector 102 is rotatedrelative to the cable 58. The lead of the mating threads on the cable 58and in the threaded boss 104 on the connector 102 will determine therate of axial relative movement between connector 102 and the cable 58.The connector 102 can be locked relative to the end of the cable 58 bythreading the lock nut 108 against the end of the boss 104.

The inside of the housing 93 has a groove 110 formed in the walls112,113,114 thereof. The groove 110 is formed in alignment with thewasher 99 on the end of the spool 62 when the spool 62 is in the neutralposition in the valve in the valve body 94. The groove 110 formed in thehousing 93 can be any form of visual indication or indicator which canbe affixed or attached to the inside wall or walls 112, 113,114 of thehousing 93 and is located at the precise point where the washer 99aligns therewith when the valve is in the neutral position.

In practice, with the actuator lever 26 locked down in the neutralposition by the lockdown apparatus 70, the nut 108 on the end portion ofthe cable 58 is loosened. The connector 102 is rotated relative to thecable 58 to move the key 105 and washer 99 axially of the cable 58 untilthe washer 99 on the spool 62 is in exact alignment with the groove 110on the wall of the housing 93. At that point, the nut 108 is drawn uptight against the connector 102 to lock the connector 102 in positionwhereby the neutral position of the actuator lever 26 correspondsexactly with the neutral setting of the spool 62 of the valve.

Using the improved mechanism 92 makes it possible to accurately andpositively set the neutral position of the lever 26 and valve spool 62without the trial and error method used heretofore.

In addition, many vehicles have operating members that must be limitedin their movement so as to prevent damage to or tipping of the vehicle.One such vehicle is a crawler-type pipelayer, such as illustrated inFIG. 1, wherein the operating member is the boom 22 which, in operation,should not be moved to the vertical or oververtical position, otherwisethe boom will bend in the middle. An actuator, such as a spring can 120,see FIG. 2, is provided in alignment with one of the parts of the boom22 so that when the boom reaches approximately 88° with respect to thehorizontal, a bumper 122 on the boom 22 will engage the spring can 120moving a rod 124 and plate 126 longitudinally with respect to the can120. The plate 126 will pivot a lever 128 about a pivot axis 130 causingan interconnected link 132 to pivot a crank arm 134 affixed to a rod 136and having a second crank arm 138 affixed to said rod 136. The crank arm138 is connected to a second link 140 which pivots a crank arm 142, rod144 and a bifurcated member 146 carried by the rod. The bifurcatedmember 146 has facing pins 148 at the ends thereof which, as seen inFIGS. 2, 3, 7 and 8, align transversely to the axis of the cable and inthe path of movement of the body portion 103 of the connector 102.Assuming that the boom 22 is moving through the 88° vertical position,the rod 124 and plate 126 will actuate the linkage to pivot thebifurcated member 146 in a counterclockwise direction as viewed in FIGS.2 and 3 so that the pins 148 thereon will contact the body portion 103of the connector 102 to move the connector 102, the valve spool 62 andthe cable 58 to the right, in a manner to override the position of theactuating lever 26 and the position of the valve that is raising theboom 22 such that the movement of the valve spool 62 will shut off thevalve thereby preventing further movement of the boom 22 toward thevertical position.

It is to be understood that any operating member of a vehicle that isintended to be limited in its movement can be controlled by the presentkickout linkage arrangement so as to move the actuating lever 26 andvalve spool to a position to avoid further movement of the operatingmember beyond a safe position. The bifurcated member 146 is adjustedrelative to the connector 102 so that actuation of the kickout linkagewill move the connector 102, the valve spool 62 and the lever 26 to theneutral position. The kickout linkage being connected to the valveinstead of to the wench, reduces the number of parts in the linkage soas to simplify its operation.

We claim:
 1. In an adjusting mechanism (92) for setting a valve spool(62) and an actuating lever (26) in a particular relationship, saidvalve spool (62) extending outwardly from a valve body (94), and saidactuating lever (26) being pivotally mounted, the improvementcomprising: means for connecting said extending end of the valve spoolto said actuating lever, said means including first connecting means(99) and second connecting means (102), said first connecting means (99)being carried by said extending end of said valve spool (62), anindicator (110) located exterior of said valve body (94) along the pathof movement of said extending end of said valve spool (62) to indicate aselected position of the valve spool (62) when said first connectingmeans (99) on the spool (62) aligns with said indicator (110), a cable(58) connecting said actuating lever (26) with said second connectingmeans (102), said second connecting means (102) connecting with saidfirst connecting means (99) on said valve spool (62), means (70) forlocking said actuating lever (26) in a selected position to coincidewith the selected position indicated by said indicator (110), and means(92) for adjusting said second connecting means (102) relative to saidcable (58) to set said first connecting means (99) on the valve spool(62) in alignment with said indicator (110) when said lever (26) andvalve spool (62) are in their respective selected positions coincidingwith said particular relationship.
 2. In an adjusting mechanism (92) asclaimed in claim 1 wherein said first connecting means (99) on saidspool (62) is a radially extending member (99) and said secondconnecting means (102) on said cable (58) engages with said radiallyextending member (99) and wherein said means (92) for adjusting secondconnecting means (102) relative to said cable (58) is an axialadjustment therebetween.
 3. In an adjusting mechanism (92) as claimed inclaim 1 wherein a housing (93) is carried by said valve body (94) andreceives said valve spool (62) therein, and wherein said indicator (110)is a groove (110) formed in said housing (93) in a position to indicatethe neutral position of the valve spool (62) when the first connectingmeans (99) on the valve spool (62) aligns with said indicator (110). 4.In an adjusting mechanism (92) as claimed in claim 1 wherein said means(70) for locking said actuating lever (26) is a lockdown knob (70)having a plate (80) with a cutout (90), said plate (80) being pivotedinto position to nest the lever (26) in said cutout (90) to lock thelever (26) in a neutral position.
 5. In an adjusting mechanism (92) asclaimed in claim 1 wherein said first connecting means (99) on saidvalve spool (62) is a washer (99) and wherein said second connectingmeans (102) on said cable (58) is a connector (102) having a key (105)engaging with said washer (99), said connector (102) is threaded on saidcable (58), the connector (102) is rotatable relative to the cable (58)to advance or retract the key (105) and washer (99) relative to theindicator (110).
 6. In an adjusting mechanism (92) as claimed in claim 1wherein said lever (26) is mounted for at least pivotal movementrelative to a frame (12), a bellcrank (32) is pivotally mounted on saidframe (12), means (36) for interconnecting said lever (26) and one arm(40) of said bellcrank (32) for pivotal movement of said bellcrank (32)responsive to pivotal movement of the lever (26), said cable (58) isconnected to another arm (50) of said bellcrank (32) and to said valvespool (62), said lever (26) being pivotally moved to move said cable(58) and said valve spool (62).
 7. In an adjusting mechanism (92) for avalve spool (62) of a valve the improvement comprising: a cable (58), anactuating lever (26) connected to said cable, said valve spool (62)extending outward from a valve body (94), a housing (93) carried by thevalve body (94) into which housing (93) said valve spool (62) extends,connecting means (99) for connecting said extended end of said valvespool (62) with said cable, said connecting means (99) being positionedin said housing (93), indicator means (110) for indicating the neutralposition of said valve spool (62), said indicator means (110) beinglocated in said housing (93) to indicate a neutral position of the valvespool (62) when said connecting means (99) aligns with said indicator(110), said actuating lever (26) being located for ready access by anoperator and being mounted for at least pivotal movement about the lowerend thereof, a pivotally mounted bellcrank (32) connected to said lever(26) and to said cable (58), said cable (58) extending into said housing(93) and having a connector (102) mounted on said cable (58) and beingin connecting relationship with said connecting means (99) on said valvespool (62), means (70) for locking said lever (26) in a neutralposition, and means (92) for adjusting said connector (102) relative tosaid cable (58), said means (92) moving said connector (102) relative tothe cable (58) until said connecting means (99) on the valve spool (62)is aligned with the indicator (110) in the housing (93) to set both saidlever (26) and said valve spool (62) simultaneously in their neutralpositions.
 8. In an adjusting mechanism (92) as claimed in claim 7wherein said connecting means (99) on said valve spool (62) is a washer(99) and wherein said connector (102) is a disc (103) having a key (105)engaging with said washer (99), and wherein said means (92) foradjusting said connector (102) is a threaded connection between saiddisc (103) and said cable (58), said washer (99) is moved into alignmentwith said indicator (110) upon turning said disc (103) relative to saidcable (58).
 9. In an adjusting mechanism (92) as claimed in claim 7wherein said means for locking said actuating lever (26) is a lock-downknob (70) having a plate (80) with a cutout (90), said plate (80) beingpivoted into position to nest the lever (26) in said cutout (90) forlocking the lever (26) in the neutral position.